Submerged suction strainer for a water hose

ABSTRACT

A suction strainer, preferably for use in a dump and go tank such as used in firefighting, which, during liquid withdrawal, rests continually on the bottom of the tank so as to eliminate whirlpool and suction loss and which, when in place, has its intake immediately adjacent the bottom of the tank so that water can be withdrawn to a very low level in the tank. In one embodiment, a unitary coupling member rests in a shallow tray on the bottom of the tank and liquid in the tank is pulled past the tray, into the member via a mesh screen which removes foreign objects, and out the coupling member to a conventional firefighting hose which is connected to the coupling at a preset angle. In another embodiment of the invention, the member coupled to the hose is pivotably mounted to a guide plate which rests on the shallow tray and is fixed with respect to it, so that any antiswirl plates in the strainer always remain in parallel with the tank bottom regardless of the angle at which the dump and go tank is set.

United States Patent [72] Inventor Kenneth K. Clegg, Jr.

Rte.1, Box 80, High Point, NC. 27260 [21] Appl. No. 2,634 [22] FiledJan. 13, 1970 [45] Patented Oct. 19, 1971 [54] SUBMERGED SUCTIONSTRAINER FOR A WATER HOSE 4 Claims, 13 Drawing Figs.

[52] 11.8. C1 210/456, 210/459 [51] Int. Cl 301d 21/24 [50] Field ofSearch 210/460, 461, 462,463, 348, 455, 456, 459; 137/40; 285/274, 275

[56] References Cited UNITED STATES PATENTS 2,300,952 11/1942 May210/456 2,318,220 5/1943 Haselwood 285/275 X 2,331,332 10/1943 Latta210/455X 3,495,714 2/ 1970 Barton 210/460 Primary Examiner-ReubenFriedman Assistant Examiner-T. A. Granger AttorneyCushman, Darby &Cushman ABSTRACT: A suction strainer, preferably for use in a dump andgo tank such as used in firefighting, which, during liquid withdrawal,rests continually on the bottom of the tank so as to eliminate whirlpooland suction loss and which, when in place, has its intake immediatelyadjacent the bottom of the tank so that water can be withdrawn to a verylow level in the tank. 1n one embodiment, a unitary coupling memberrests in a shallow tray on the bottom of the tank and liquid in the tankis pulled past the tray, into the member via a mesh screen which removesforeign objects, and out the coupling member to a conventionalfirefighting hose which is connected to the coupling at a preset angle.In another embodiment of the invention, the member coupled to the hoseis pivotably mounted to a guide plate which rests on the shallow trayand is fixed with respect to it, so that any antiswirl plates in thestrainer always remain in parallel with the tank bottom regardless ofthe -,angle at which the dump and go tank is set.

PATENTEDUU 19 IBYI sum 16F '2 3,613,894

ATTORNEYS SUIBMERGEID SUCTION STRAINER FOR A WATER HOSE BRIEFDESCRIPTION OF THE PRIOR ART AND SUMMARY OF THE INVENTION The inventionrelates to a method and apparatus for removing firefighting liquid, suchas water, from a tank such as a stop and go tank.

One firefighting technique which is increasingly relied upon,particularly in fighting rural fires, involves use of a stop and gotank. This tank is simply a portable container which is carried to thesite of the fire, set up and then filled with firefighting liquid whichthen can be withdrawn through conventional hoses for extinguishing thefire. The tank thus serves in place of the water distribution systemavailable in urban areas, and is periodically refilled by means of tanktrucks which shuttle between the site of the fire and a convenientsource of firefighting liquid, such as water, to keep the tank filled tothe level necessary to maintain feed to the hoses spraying the liquidonto the fire.

Because the liquid which is used to replenish the dump and go tankfrequently contains foreign objects which tend to clog the strainers andhoses and otherwise create problems, it is usually desirable to, atleast some extent, strain the liquid before it is removed from the tankby a hose to be sprayed on the fire or otherwise employed in thefirefighting operation. A round strainer, which is simply an elongatedcylindrical member of plastic or other similar material with a pluralityof small openings around its circumference, has been used in the pastfor this purpose. This type of strainer, however, is not totallysatisfactory for withdrawing water from a tank in a stop and gooperation, first, because it loses suction when the water level in thetank is reduced below about 14 inches, and second, because it does notalways remain properly beneath the level of water in the tank,particularly when the tank is being refilled. This limitation on thelevel to which the water in the tank can be reduced is particularlyimportant since, in a conventional 1,500-gallon tank, each inch of waterrepresents about 50 gal. of liquid, and accordingly this type of roundstrainer cannot remove the final 700 gal. of water in the tank. Keepingthe level in the tank above that point may prove difficult and maysubstantially hinder the firefighting effort.

Another type of strainer which has been used is commonly termed afloat-dock strainer and is simply a float member with an aperturedstrainer attached thereto with the apertures below the surface of thewater. While this type of arrangement is capable of continuing thepumping operation until the water level in the tank is reduced to about6 inches, it too has severe disadvantages which render it less thancompletely satisfacto- Obviously the most efficient way to use dump andgo tanks is to refill them as quickly as possible, since the less timerequired to transfer the liquid load from the shuttle truck to the tank,the more water can be carried by that truck in any given length of time.Thus, currently preferred techniques emphasize rapid dumping into thetank and this procedure has been found to considerably improvefirefighting ability. However, when water is entering the tank at a highrate such as is desirable with fast dump methods, for example, at therate of 1,200 gallons per minute, floating strainers frequently ride toohigh in the water because of the whirlpool effect of the rapidlyentering water with the result that suction to the hose is temporarilylost. Loss of suction means that the flow of water to the nozzle isinterrupted with consequent danger to the firefighter and disruption ofthe firefighting effort.

The present invention relates to a strainer which is particularlysuitable for use with a dump and go tank and which continually rides onthe bottom of the tank. Further, the novel suction strainer of thisinvention includes a shallow tray on which a coupling member rests sothat the water in the tank enters the coupling member via the shallowtray after passage through a mesh screen or similar straining filter. Bythis arrangement, not only is the danger of whirlpool and suction loss,which can result when water is being fast dumped into the tank,eliminated, but water can be withdrawn to a very low level in the stopand go tank, for example, 2 inches.

In another embodiment of the invention, the coupling member includes twoportions, one resting on the tray and fixed with respect to it and theother pivotably mounted on the first portion along an axis parallel tothe bottom of the tank and perpendicular to the direction which water iswithdrawn so that the strainer is capable of being used on any trayregardless of whether it is level or not. Even further, this swiveltypecoupling permits antiswirl plates to be installed parallel with the tankbottom if desired.

Many other objects and purposes of the invention will become clear fromthe following detailed description of the drawings. a

A BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a perspective view ofone embodiment of the invention with a hose coupled thereto for removingliquid from the bottom of a tank, such as a stop and go tank.

FIG. 2 shows a side view of the coupling member of the embodiment ofFIG. 1.

FIG. 3 shows a front view of the coupling member of the embodiment ofFIG. 1.

FIG. 4 shows a top view of the tray of the embodiment of FIG. 1.

FIG. 5 shows a side view of the tray of the embodiment of FIG. 1.

FIG. 6 shows a perspective view of another embodiment of the inventionwhereby the pickup body is hinged on an axis perpendicular to the linealong which water is withdrawn by the hose.

FIG. 7 shows a top view of the stationary member of the embodiment ofFIG. 6.

FIG. 8 shows a side view of the stationary member of the embodiment ofFIG. 6.

FIG. 9 shows a top view of the tray of the embodiment of FIG. 6.

FIG. 10 shows a side view of the tray of the embodiment of FIG. 6.

FIG. 11 shows a side view of the pivoted coupling member of theembodiment of FIG. 6.

FIG. 12 FIG. 12 shows a top view of the pivoted coupling member of theembodiment of FIG. 6.

FIG. 13 shows a bottom view of the pivoted coupling member of theembodiment of FIG. 6.

DETAILED DESCRIPTION OF THE DRAWINGS Reference is now made to FIGS. 1-5which show one embodiment of the invention of this application. Asdiscussed briefly above, novel strainer 18 illustrated in FIGS. 1-5 isdesigned to ride continuously on a tank bottom regardless of the rate ofwater flow in and out of the tank, to withdraw water from the tankunhampered by refilling of the tank regardless of the rate of refilling,and to retain suction even when water is discharged into the tank at arate of over 1,200 gallons per minute. Further in this arrangement anyantiswirl plate employed will be kept parallel with the tank bottomregardless of the terrain on which the tank rests.

As can be seen in FIG. 1, strainer 18 is connected by a conventionalcoupler 20 to a hose 22 which applies suction to withdraw water from thetank and deliver it to the site of the fire. As shown in FIGS. 2-5,strainer 18 is comprised of a coupling member 24 which is preferablyformed as an integral member with an opening in the bottom for suckingup water from a tray 28, a hollow interior passage through which thewater passes and a tubular extension 26 for connection to csnventionalcoupler 20. The tubular extension 26 may be provided with exterior orinterior threads. The hollow interior passage of member 24 isspecifically designed so as to direct the flow of water as efficientlyas possible from its entrance at the bottom of member 24 to extension 26through which the water exits. Thus, in the embodiment of FIGS. 1-5 theportion of member 24 furtherest from extension 26 has a height less thanthe height of member 24 adjacent tubular extension 26. The humped shapeof strainer 18 likewise contributes to the rapid rate at which water canbe withdrawn frm the tank. In one embodiment of the inventionconstructed according to the arrangement shown in FIGS. 1-5, it wasfound that the flow rate at which water could be withdrawn from aconventional stop and go tank was up to twice the rate at whichconventional pumps could conventionally withdraw liquid under similarconditions.

Referring to FIGS. 4 and 5, member 24 rests on a shallow tray 28 whichis provided at its ends with two seats 30 and 32 upon which member 24rests. Preferably, member 24 is bolted or otherwise fixed securely toshallow tray 28. As can be seen in FIG. 5, tray 28 is extremely shallowand, in one embodiment of the invention, the tray height, exclusive ofthe seats 30 and 32, was made to be 1 inch. It was found that, with thisparticular embodiment, water could be withdrawn down to a level of 2inches in a relatively level stop and go tank.

A mesh screen 34 which is conventional in nature is preferably attachedto the bottom of the member 26 to filter, at least in part, the waterentering the opening in the bottom of member 24 around tray 28. In theembodiment of the invention which was constructed with a tray 28 havinga l-inch height, the dimensions T, U, X, Y and Z in FIGS. 2 and 3 weremade to be 4 inches, 3 A inches, 7 inches, 10 inches and inchesrespectively. These particular dimensions were found to be quitesatisfactory.

Reference is now made to FIGS. 6-13 which show another embodiment of theinvention similar to the arrangement of FIGS. I-5. However, in thisstrainer, an additional stationary member is provided and the couplingmember is adapted to pivot about an axis in this stationary member sothat the angle that the hose is attached to the member with respect tothe bottom of the stop and go tank and also with respect to the shallowtray 52 can be altered so that the unit can be easily employed in anylocation regardless of the angle at which the stop and go tank is set.

As in the embodiment of FIGs. 1-5, tray 52 shown in FIGS. 9 and I0 isquite shallow and is provided with a rim 54 around its interior of theorder of about 2 inches in height. The stationary member 56 illustratedin FIGS. 7 and 8 is designed to set in tray 52 so as to provide asuitable clearance for water to be sucked up from tray 52 into pivotablecoupling member 58. Member 50, as can be seen in FIG. 13, has an opening64 in its bottom for receiving the water which is sucked into tray 52and up through opening 64 to pivotable coupling member 50. Further, ascan be seen in FIG. 8, stationary member 56 is pivotably connected tomember 50 so that member 50 is pivotable about axis 62 which is parallelto the bottom of the tank and perpendicular to the direction water flowsout extension member 66. The extending tubular member 66 of the couplingmember 50 is provided with threads for engaging a coupler 70 which isshown at FIG. 11 and which connects tubular extension 66 to a suitablehose.

Many changes and modifications can be made in the embodiments of theinvention illustrated in FIGS. ll3, and the scope of this invention isintended to be limited only by the scope of the appended claims.

What is claimed is:

l. A suction strainer comprising:

a shallow tray for resting on the bottom of a tank,

a coupling member adapted to rest on said tray and having an opening inthe bottom thereof adjacent said tray for withdrawing fluid from saidtank so that said fluid can be withdrawn to a low level, means forcoupling said member to a hose so that said hose receives said fluidfrom said member, and an interior passage for directing said fluid fromsaid opening to said coupling means, and

a stationary member pivotable connected to said coupling member so thatsaid coupling member is pivotable about an axis substantially parallelwith the bottom of said tank and substantially perpendicular to thedirection which said fluid flows into said hose from said couplingmeans. 2. A strainer as in claim 1 further including a mesh screencovering said opening for filtering said fluid.

3. A strainer as in claim 1 wherein said coupling means is at one end ofsaid coupling member, the height of said coupling member is greatestadjacent said coupling means and decreases continuously toward the otherend of said coupling member.

4. A strainer as in claim I wherein said coupling means is a threadedtubular extension of said coupling member.

1. A suction strainer comprising: a shallow tray for resting on thebottom of a tank, a coupling member adapted to rest on said tray andhaving an opening in the bottom thereof adjacent said tray forwithdrawing fluid from said tank so that said fluid can be withdrawn toa low level, means for coupling said member to a hose so that said hosereceives said fluid from said member, and an interior passage fordirecting said fluid from said opening to said coupling means, and astationary member pivotable connected to said coupling member so thatsaid coupling member is pivotable about an axis substantially parallelwith the bottom of said tank and substantially perpendicular to thedirection which said fluid flows into said hose from said couplingmeans.
 2. A strainer as in claim 1 further including a mesh screencovering said opening for filtering said fluid.
 3. A strainer as inclaim 1 wherein said coupling means is at one end of said couplingmember, the height of said coupling member is greatest adjacent saidcoupling means and decreases continuously toward the other end of saidcoupling member.
 4. A strainer as in claim 1 wherein said coupling meansis a threaded tubular extension of said coupling member.